This invention relates generally to a device having relatively rotatable parts for holding a flexible power supply cable affixed thereto.
The relatively rotatable parts may comprise, for example, a stationary base and a relatively movable arm of a crane installation, or a movable part of a pneumatic conveyor, in which the power supply unit is located in the stationary base. Thus, all connections, such as electrical lines, hydraulic lines and/or air conveyor lines must be arranged between the stationary base and the moving part in such a manner as to not impede the relative turning movement. The lines must therefore follow the turning motion. For electrical conductors, turning movement can be facilitated by the provision of slip rings for power transfer in a purely electrical power transmission. Such an arrangement, however, requires special designs and is therefore costly. For hydraulic lines and for air conveyor lines, still other solutions must be found.